Abstract. This paper describes an operational retrieval algorithm for the sand/dust
storm (SDS) from FY-2C/S-VISSR (Stretched-Visible and Infrared Spin-Scan
Radiometer) developed at the National Satellite Meteorological Center (NSMC)
of China. This algorithm, called Dust Retrieval Algorithm based on
Geostationary Imager (DRAGI), is based on the optical and radiative physical
properties of SDS in mid-infrared and thermal infrared spectral regions as
well as the observation of all bands in the geostationary imager, which
include the Brightness Temperature Difference (BTD) in split window
channels, Infrared Difference Dust Index (IDDI) and the ratio of middle
infrared reflectance to visible reflectance. It also combines the visible
and water vapor bands observation of the geostationary imager to identify
the dust clouds from the surface targets and meteorological clouds. The
output product is validated by and related to other dust aerosol
observations such as the synoptic weather reports, surface visibility,
aerosol optical depth (AOD) and ground-based PM10 observations. Using the
SDS-IDD product and a data assimilation scheme, the dust forecast model
CUACE/Dust achieved a substantial improvement to the SDS predictions in
spring 2006.